Blue House on San Isidro,
Agreed on Sully's
One of the best seafood restaurants in Santo Domingo is Sully. It's definitely worth the trip.
Their contact info can be found in the directory section of dr1guide.com along with a Google Map: Sully - Seafood - Restaurants - dr1guide Directory
Blue house on San Isidro is closed, but they have another in the city, if I'm not mistaken.
I was also told that the owners of Blue House are the same as Stir & Fry..